Scientists have urged the government to consider the full impact of global warming when drawing up plans to protect Britain from flooding. A study from the Met Office's Hadley Centre predicts that river levels will rise higher than anticipated because existing computer models do not take into account the effects of climate change on plant life.

In a warmer world, say scientists, less water will be drawn up by plants, causing greater flows into rivers like the Thames and the Severn, which burst their banks last month bringing chaos to large parts of England.

The study results, published today in the journal Nature, show that, if carbon dioxide emissions go unchecked, climate change and its effect on plants will have increased river flow by 13% in Europe over the course of 300 years.

"Current impact assessments will need to be reworked," said Richard Betts, the climate scientist who led the research.

The study comes weeks after floods swept through several areas of the UK. Although the water has receded, thousands of people are homeless or living in the dirty shells of their houses.

"It's been terrible," said Mr Jasper, a 50-year-old decorator from Gloucester. "The insurance company has been hopeless. We've been living in horrible conditions while we wait for them to tell us what's happening. It's affecting my health and my partner is off work because of stress." Finally this week a surveyor gave him the go-ahead to start hacking away at his walls. "At this rate it will be next Christmas, never mind this, before we are right," Mr Jasper said.

Next door is empty. It is the home of 89-year-old Gladys Davies, now living with her daughter, Eunice Mann. It is not clear when, or if, she will be able to move back in. Like many of the most vulnerable people caught in the floods she did not have insurance. "We haven't dared bring her back here. I don't think she could bear to see what's happened," said Mrs Mann.

The death of one elderly woman in the street has already been blamed on the shock of returning to a wrecked house.

Figures seen by the Guardian show the scale of the problem as Gloucestershire and Worcestershire try to recover from the biggest floods on record. Gloucestershire county council estimates it will have a bill of between £50m-£55m. Fixing up damaged roads, footpaths and bridges will cost £25m alone, an entire year's budget for the highways. Almost £3m will be spent on repairs to 53 schools in the area.

Private companies have also taken a hit from which many will not recover. The flooding directly affected 500 businesses and another 15,000 suffered after their water supply was turned off for a week.

There have been visits by ministers to the county but the perception is that little money is coming through. So far, £2.5m has been made available for district councils to pay for recovery from the floods and £600,000 has been handed over for schools. But the council has yet to meet the Department for Transport over the massive highways bill, and fears some roads that were seriously damaged will stay shut for the foreseeable future.

In Hull, where more than 7,000 homes were flooded and a man died in a storm drain, the council is also counting the cost of the rains, which could be as high as £200m. An interim report says the city's drainage system was overwhelmed by the water because its flood protection plans were based on such heavy rainfall arriving only one year in every 30.

The study also highlighted problems arising from various bodies, including the Environment Agency, and councils and water companies, being responsible for different parts of the drainage system. That difficulty is likely to be replicated elsewhere. The report also urged the Environment Agency to find out whether its flood warning systems could be expanded to cover flash rainfall.

The picture in Worcestershire is also bleak and there are fears that the county's flood bill could be in the region of £5m- £10m - a big chunk of the £15m it holds in its reserves.

Tourism has taken a huge hit in Worcestershire with two sporting attractions, Worcester Racecourse and the New Road county cricket ground, out of action for the season. The breaking news on the cricket club's website yesterday was that grass had been seen at the site.

In the Malvern hills town of Upton upon Severn, which was cut off during the floods, riverside pubs are stricken and shopkeepers along the high street report poor business. "It has been a ghost town in these last weeks," said Kate Harding, landlady of Ye Olde Anchor Inn, who defiantly handed out glasses of pink champagne on the first Sunday of the floods.

The village of Sandhurst, which stands on the banks of the Severn in Gloucestershire, was one of the most isolated areas during the floods, accessible only by boat or aircraft. Now, however, life is beginning to return to normal.

At Abloads Court, a mainly 17th century farmhouse, three ponies were this week grazing in the paddock. They achieved worldwide fame after the Guardian pictured them living in the Sandhurst house during the floods. Their owner, Dawn Melvin said: "The horses loved the boot room. They spent five days in there. When we moved back into the house we left the door open so they could still get back in when they wanted."

Her neighbours, Sandra Wickenden and Dave Munn, are living in a caravan in their own garden. Will they move out? "No, that's definitely not on the agenda," said Mr Munn. "If it floods, it floods. You have to accept it and get on. We're staying."